GB 1495097 discloses a marking powder containing a pigment, an adhesion agent, and aluminium powder. The legibility of markings applied using such a known marking powder is found in practice to diminish after only a few weeks. Moreover, on some bodies such as steel slabs and billets stored outdoors, contamination depositing on the markings is disadvantageous. For example, particles of rust are found to deposit on the markings thereby further diminishing legibility.